Muḥsin Mahdī (Arabic: محسن مهدي‎) (June 21, 1926–July 9, 2007) was an Iraqi-American islamologist and arabist. He was a leading authority on Arabian history, philology, and philosophy. His best-known work was the first critical edition of the One Thousand and One Nights.

He was born and raised in the Shiite pilgrimage city of Kerbala, Iraq. After finishing high school in Baghdad, he was awarded a government scholarship to study at the American University of Beirut, where he earned both a B.B.A. and a B.A. in philosophy. He taught for a year at the University of Baghdad before coming to the United States in 1948, where he earned an M.A. and Ph.D.(1954) at the University of Chicago. Here he studied at the Oriental Institute under Nabia Abbott and began his life-long exploration of political philosophy under the guidance of Leo Strauss. His wrote his dissertation on Ibn Khaldun. After two more years in Baghdad, Mahdi returned to Chicago, where he taught in the Department of Near Eastern Languages and Civilizations from 1958-1969. At Harvard University (from 1969 until his retirement in 1996),as James Richard Jewett Professor of Arabic, he served as director of the Center for Middle Eastern Studies and also as Chairman of the Department of Near Eastern Languages and Civilizations.